29d06de35d
See [31137]. See #30891. git-svn-id: https://develop.svn.wordpress.org/trunk@31141 602fd350-edb4-49c9-b593-d223f7449a82
417 lines
12 KiB
PHP
417 lines
12 KiB
PHP
<?php
|
|
/**
|
|
* A class for displaying various tree-like structures.
|
|
*
|
|
* Extend the Walker class to use it, see examples below. Child classes
|
|
* do not need to implement all of the abstract methods in the class. The child
|
|
* only needs to implement the methods that are needed.
|
|
*
|
|
* @since 2.1.0
|
|
*
|
|
* @package WordPress
|
|
* @abstract
|
|
*/
|
|
class Walker {
|
|
/**
|
|
* What the class handles.
|
|
*
|
|
* @since 2.1.0
|
|
* @access public
|
|
* @var string
|
|
*/
|
|
public $tree_type;
|
|
|
|
/**
|
|
* DB fields to use.
|
|
*
|
|
* @since 2.1.0
|
|
* @var array
|
|
*/
|
|
public $db_fields;
|
|
|
|
/**
|
|
* Max number of pages walked by the paged walker
|
|
*
|
|
* @since 2.7.0
|
|
* @var int
|
|
*/
|
|
public $max_pages = 1;
|
|
|
|
/**
|
|
* Whether the current element has children or not.
|
|
*
|
|
* To be used in start_el().
|
|
*
|
|
* @since 4.0.0
|
|
* @var bool
|
|
*/
|
|
public $has_children;
|
|
|
|
/**
|
|
* Starts the list before the elements are added.
|
|
*
|
|
* The $args parameter holds additional values that may be used with the child
|
|
* class methods. This method is called at the start of the output list.
|
|
*
|
|
* @since 2.1.0
|
|
* @abstract
|
|
*
|
|
* @param string $output Passed by reference. Used to append additional content.
|
|
* @param int $depth Depth of the item.
|
|
* @param array $args An array of additional arguments.
|
|
*/
|
|
public function start_lvl( &$output, $depth = 0, $args = array() ) {}
|
|
|
|
/**
|
|
* Ends the list of after the elements are added.
|
|
*
|
|
* The $args parameter holds additional values that may be used with the child
|
|
* class methods. This method finishes the list at the end of output of the elements.
|
|
*
|
|
* @since 2.1.0
|
|
* @abstract
|
|
*
|
|
* @param string $output Passed by reference. Used to append additional content.
|
|
* @param int $depth Depth of the item.
|
|
* @param array $args An array of additional arguments.
|
|
*/
|
|
public function end_lvl( &$output, $depth = 0, $args = array() ) {}
|
|
|
|
/**
|
|
* Start the element output.
|
|
*
|
|
* The $args parameter holds additional values that may be used with the child
|
|
* class methods. Includes the element output also.
|
|
*
|
|
* @since 2.1.0
|
|
* @abstract
|
|
*
|
|
* @param string $output Passed by reference. Used to append additional content.
|
|
* @param object $object The data object.
|
|
* @param int $depth Depth of the item.
|
|
* @param array $args An array of additional arguments.
|
|
* @param int $current_object_id ID of the current item.
|
|
*/
|
|
public function start_el( &$output, $object, $depth = 0, $args = array(), $current_object_id = 0 ) {}
|
|
|
|
/**
|
|
* Ends the element output, if needed.
|
|
*
|
|
* The $args parameter holds additional values that may be used with the child class methods.
|
|
*
|
|
* @since 2.1.0
|
|
* @abstract
|
|
*
|
|
* @param string $output Passed by reference. Used to append additional content.
|
|
* @param object $object The data object.
|
|
* @param int $depth Depth of the item.
|
|
* @param array $args An array of additional arguments.
|
|
*/
|
|
public function end_el( &$output, $object, $depth = 0, $args = array() ) {}
|
|
|
|
/**
|
|
* Traverse elements to create list from elements.
|
|
*
|
|
* Display one element if the element doesn't have any children otherwise,
|
|
* display the element and its children. Will only traverse up to the max
|
|
* depth and no ignore elements under that depth. It is possible to set the
|
|
* max depth to include all depths, see walk() method.
|
|
*
|
|
* This method should not be called directly, use the walk() method instead.
|
|
*
|
|
* @since 2.5.0
|
|
*
|
|
* @param object $element Data object.
|
|
* @param array $children_elements List of elements to continue traversing.
|
|
* @param int $max_depth Max depth to traverse.
|
|
* @param int $depth Depth of current element.
|
|
* @param array $args An array of arguments.
|
|
* @param string $output Passed by reference. Used to append additional content.
|
|
* @return null Null on failure with no changes to parameters.
|
|
*/
|
|
public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
|
|
|
|
if ( !$element )
|
|
return;
|
|
|
|
$id_field = $this->db_fields['id'];
|
|
$id = $element->$id_field;
|
|
|
|
//display this element
|
|
$this->has_children = ! empty( $children_elements[ $id ] );
|
|
if ( isset( $args[0] ) && is_array( $args[0] ) ) {
|
|
$args[0]['has_children'] = $this->has_children; // Backwards compatibility.
|
|
}
|
|
|
|
$cb_args = array_merge( array(&$output, $element, $depth), $args);
|
|
call_user_func_array(array($this, 'start_el'), $cb_args);
|
|
|
|
// descend only when the depth is right and there are childrens for this element
|
|
if ( ($max_depth == 0 || $max_depth > $depth+1 ) && isset( $children_elements[$id]) ) {
|
|
|
|
foreach( $children_elements[ $id ] as $child ){
|
|
|
|
if ( !isset($newlevel) ) {
|
|
$newlevel = true;
|
|
//start the child delimiter
|
|
$cb_args = array_merge( array(&$output, $depth), $args);
|
|
call_user_func_array(array($this, 'start_lvl'), $cb_args);
|
|
}
|
|
$this->display_element( $child, $children_elements, $max_depth, $depth + 1, $args, $output );
|
|
}
|
|
unset( $children_elements[ $id ] );
|
|
}
|
|
|
|
if ( isset($newlevel) && $newlevel ){
|
|
//end the child delimiter
|
|
$cb_args = array_merge( array(&$output, $depth), $args);
|
|
call_user_func_array(array($this, 'end_lvl'), $cb_args);
|
|
}
|
|
|
|
//end this element
|
|
$cb_args = array_merge( array(&$output, $element, $depth), $args);
|
|
call_user_func_array(array($this, 'end_el'), $cb_args);
|
|
}
|
|
|
|
/**
|
|
* Display array of elements hierarchically.
|
|
*
|
|
* Does not assume any existing order of elements.
|
|
*
|
|
* $max_depth = -1 means flatly display every element.
|
|
* $max_depth = 0 means display all levels.
|
|
* $max_depth > 0 specifies the number of display levels.
|
|
*
|
|
* @since 2.1.0
|
|
*
|
|
* @param array $elements An array of elements.
|
|
* @param int $max_depth The maximum hierarchical depth.
|
|
* @return string The hierarchical item output.
|
|
*/
|
|
public function walk( $elements, $max_depth) {
|
|
|
|
$args = array_slice(func_get_args(), 2);
|
|
$output = '';
|
|
|
|
if ($max_depth < -1) //invalid parameter
|
|
return $output;
|
|
|
|
if (empty($elements)) //nothing to walk
|
|
return $output;
|
|
|
|
$parent_field = $this->db_fields['parent'];
|
|
|
|
// flat display
|
|
if ( -1 == $max_depth ) {
|
|
$empty_array = array();
|
|
foreach ( $elements as $e )
|
|
$this->display_element( $e, $empty_array, 1, 0, $args, $output );
|
|
return $output;
|
|
}
|
|
|
|
/*
|
|
* Need to display in hierarchical order.
|
|
* Separate elements into two buckets: top level and children elements.
|
|
* Children_elements is two dimensional array, eg.
|
|
* Children_elements[10][] contains all sub-elements whose parent is 10.
|
|
*/
|
|
$top_level_elements = array();
|
|
$children_elements = array();
|
|
foreach ( $elements as $e) {
|
|
if ( 0 == $e->$parent_field )
|
|
$top_level_elements[] = $e;
|
|
else
|
|
$children_elements[ $e->$parent_field ][] = $e;
|
|
}
|
|
|
|
/*
|
|
* When none of the elements is top level.
|
|
* Assume the first one must be root of the sub elements.
|
|
*/
|
|
if ( empty($top_level_elements) ) {
|
|
|
|
$first = array_slice( $elements, 0, 1 );
|
|
$root = $first[0];
|
|
|
|
$top_level_elements = array();
|
|
$children_elements = array();
|
|
foreach ( $elements as $e) {
|
|
if ( $root->$parent_field == $e->$parent_field )
|
|
$top_level_elements[] = $e;
|
|
else
|
|
$children_elements[ $e->$parent_field ][] = $e;
|
|
}
|
|
}
|
|
|
|
foreach ( $top_level_elements as $e )
|
|
$this->display_element( $e, $children_elements, $max_depth, 0, $args, $output );
|
|
|
|
/*
|
|
* If we are displaying all levels, and remaining children_elements is not empty,
|
|
* then we got orphans, which should be displayed regardless.
|
|
*/
|
|
if ( ( $max_depth == 0 ) && count( $children_elements ) > 0 ) {
|
|
$empty_array = array();
|
|
foreach ( $children_elements as $orphans )
|
|
foreach( $orphans as $op )
|
|
$this->display_element( $op, $empty_array, 1, 0, $args, $output );
|
|
}
|
|
|
|
return $output;
|
|
}
|
|
|
|
/**
|
|
* paged_walk() - produce a page of nested elements
|
|
*
|
|
* Given an array of hierarchical elements, the maximum depth, a specific page number,
|
|
* and number of elements per page, this function first determines all top level root elements
|
|
* belonging to that page, then lists them and all of their children in hierarchical order.
|
|
*
|
|
* $max_depth = 0 means display all levels.
|
|
* $max_depth > 0 specifies the number of display levels.
|
|
*
|
|
* @since 2.7.0
|
|
*
|
|
* @param int $max_depth The maximum hierarchical depth.
|
|
* @param int $page_num The specific page number, beginning with 1.
|
|
* @return string XHTML of the specified page of elements
|
|
*/
|
|
public function paged_walk( $elements, $max_depth, $page_num, $per_page ) {
|
|
|
|
/* sanity check */
|
|
if ( empty($elements) || $max_depth < -1 )
|
|
return '';
|
|
|
|
$args = array_slice( func_get_args(), 4 );
|
|
$output = '';
|
|
|
|
$parent_field = $this->db_fields['parent'];
|
|
|
|
$count = -1;
|
|
if ( -1 == $max_depth )
|
|
$total_top = count( $elements );
|
|
if ( $page_num < 1 || $per_page < 0 ) {
|
|
// No paging
|
|
$paging = false;
|
|
$start = 0;
|
|
if ( -1 == $max_depth )
|
|
$end = $total_top;
|
|
$this->max_pages = 1;
|
|
} else {
|
|
$paging = true;
|
|
$start = ( (int)$page_num - 1 ) * (int)$per_page;
|
|
$end = $start + $per_page;
|
|
if ( -1 == $max_depth )
|
|
$this->max_pages = ceil($total_top / $per_page);
|
|
}
|
|
|
|
// flat display
|
|
if ( -1 == $max_depth ) {
|
|
if ( !empty($args[0]['reverse_top_level']) ) {
|
|
$elements = array_reverse( $elements );
|
|
$oldstart = $start;
|
|
$start = $total_top - $end;
|
|
$end = $total_top - $oldstart;
|
|
}
|
|
|
|
$empty_array = array();
|
|
foreach ( $elements as $e ) {
|
|
$count++;
|
|
if ( $count < $start )
|
|
continue;
|
|
if ( $count >= $end )
|
|
break;
|
|
$this->display_element( $e, $empty_array, 1, 0, $args, $output );
|
|
}
|
|
return $output;
|
|
}
|
|
|
|
/*
|
|
* Separate elements into two buckets: top level and children elements.
|
|
* Children_elements is two dimensional array, e.g.
|
|
* $children_elements[10][] contains all sub-elements whose parent is 10.
|
|
*/
|
|
$top_level_elements = array();
|
|
$children_elements = array();
|
|
foreach ( $elements as $e) {
|
|
if ( 0 == $e->$parent_field )
|
|
$top_level_elements[] = $e;
|
|
else
|
|
$children_elements[ $e->$parent_field ][] = $e;
|
|
}
|
|
|
|
$total_top = count( $top_level_elements );
|
|
if ( $paging )
|
|
$this->max_pages = ceil($total_top / $per_page);
|
|
else
|
|
$end = $total_top;
|
|
|
|
if ( !empty($args[0]['reverse_top_level']) ) {
|
|
$top_level_elements = array_reverse( $top_level_elements );
|
|
$oldstart = $start;
|
|
$start = $total_top - $end;
|
|
$end = $total_top - $oldstart;
|
|
}
|
|
if ( !empty($args[0]['reverse_children']) ) {
|
|
foreach ( $children_elements as $parent => $children )
|
|
$children_elements[$parent] = array_reverse( $children );
|
|
}
|
|
|
|
foreach ( $top_level_elements as $e ) {
|
|
$count++;
|
|
|
|
// For the last page, need to unset earlier children in order to keep track of orphans.
|
|
if ( $end >= $total_top && $count < $start )
|
|
$this->unset_children( $e, $children_elements );
|
|
|
|
if ( $count < $start )
|
|
continue;
|
|
|
|
if ( $count >= $end )
|
|
break;
|
|
|
|
$this->display_element( $e, $children_elements, $max_depth, 0, $args, $output );
|
|
}
|
|
|
|
if ( $end >= $total_top && count( $children_elements ) > 0 ) {
|
|
$empty_array = array();
|
|
foreach ( $children_elements as $orphans )
|
|
foreach( $orphans as $op )
|
|
$this->display_element( $op, $empty_array, 1, 0, $args, $output );
|
|
}
|
|
|
|
return $output;
|
|
}
|
|
|
|
public function get_number_of_root_elements( $elements ){
|
|
|
|
$num = 0;
|
|
$parent_field = $this->db_fields['parent'];
|
|
|
|
foreach ( $elements as $e) {
|
|
if ( 0 == $e->$parent_field )
|
|
$num++;
|
|
}
|
|
return $num;
|
|
}
|
|
|
|
// Unset all the children for a given top level element.
|
|
public function unset_children( $e, &$children_elements ){
|
|
|
|
if ( !$e || !$children_elements )
|
|
return;
|
|
|
|
$id_field = $this->db_fields['id'];
|
|
$id = $e->$id_field;
|
|
|
|
if ( !empty($children_elements[$id]) && is_array($children_elements[$id]) )
|
|
foreach ( (array) $children_elements[$id] as $child )
|
|
$this->unset_children( $child, $children_elements );
|
|
|
|
if ( isset($children_elements[$id]) )
|
|
unset( $children_elements[$id] );
|
|
|
|
}
|
|
|
|
} // Walker
|